REDUCTION OF BENZENE RING AND OF OLEFINIC DOUBLE BOND BY ELECTROLYTICALLY GENERATED ELECTRONS

Benzene and olefins can be reduced electrochemically in ethanol containing hexamethylphosphoramide (HMPA). The reduction of these substrates is believed to be due to electrochemically generated solvated electrons. The relative amounts of cyclohexadiene, cyclohexene, and cyclohexane obtained in the reduction of benzene depend on ethanol concentration, current density, and temperature in a manner consistent with the proposed mechanism. Benzene can also be reduced electrochemically in pure ethanol. In the absence of HMPA, however, the current efficiency is only of the order of 1% as compared to a current efficiency of 95% in ethanol HMPA. © 1969, American Chemical Society. All rights reserved.